Abstract

The final chapter intends to revive reason or rationality as a source of the a priori in a roughly Kantian spirit. Therefore, the two notions of apriority introduced in Chapter 6 and their dynamic character are more thoroughly explained. This helps grasping the conceptual a priori and its three forms of appearance. However, concepts are not the only source of the a priori. The rational structure of reasons is so as well, as is unfolded in a series of principles. The starting point is the Basic Empiricist principle that is the core of all empiricist attitudes and that is shown to entail two coherence principles expressing something like the unity of science. Then the chapter proceeds to the fundamental issue of the truth-conduciveness of reasons and argues that the Basic Empiricist principle should be strengthened to the Basic Belief-Truth and Basic Reason-Truth Connection, which are further amended by certain stability assumptions. On the basis of Chapter 14, these stronger principles provably entail a weak principle of causality. The moral of all this is: there is substantial and rigorous theorizing about the a priori beyond the merely conceptual a priori.